1. Field of the Invention
The invention relates to the field of material handling systems. More particularly, the invention relates to a transfer system for safely moving flowable materials from one containment to another one. More particularly yet, the invention relates to a device for connecting and locking flowable-material transfer apparatus to a flowable-material container.
2. Description of the Prior Art
Transferring flowable material from one container to another is a common task in industry and commerce. The term “flowable materials” as used herein includes industrial solvents and petroleum products, foodstuffs, toxic and non-toxic materials, combustible and non-combustible materials. The term “flowable” includes liquids, gases, slurries, sludges, pastes, flowable solids, such as powdered, pulverized, granulated, pelletized, and encapsulated material, and other material that may flow naturally or be made to flow from one place of containment to another. The methods of transfer vary with the reasons for removal, the nature of the material, and the use to which the material is to be put. Whatever the reason for transferring a material from one container to another, the act of transfer always represents a heightened risk to the secure containment of the material. The risk is particularly great when the material is toxic, corrosive, or otherwise hazardous to the environment, or when working under large volumes of pressurized material. Increased awareness of environmental hazards and increased sensitivity to workers' safety have led to greater focus on ensuring the safety and reliability of material handling systems. Consequently, apparatuses and devices that help prevent or reduce the risk of spillage or leakage of flowable material are extremely desirable and useful, both for reasons of general health and welfare and for economic reasons.
Many devices and systems have been developed to address the problem of unintentional escape of flowable material, be it by spillage or gaseous escape, during the transfer of flowable materials from one containment vessel to another. Most of these involve attaching external apparatus to the source containment vessel or system that enables the flowable material to be moved to a destination containment vessel or system through a completely enclosed conduit system that may comprise hose, tubing, pipe, ductwork, or other conduit, or may simply be the opening between two adjacent, “docked” systems. Two major sources of failure of a material transfer system are inherently present when transferring flowable materials: 1) the very act of connecting or disconnecting the external apparatus to the source container; and 2) failure of the connector device. For this reason, connector devices and valves are critical components of flowable-material transfer systems.
U.S. Pat. No. 5,765,612, issued to the inventor of the present invention, discloses apparatus for safely draining motor oil from the oil pan of an engine crank case. The apparatus includes a three-part connector device. One part is semi-permanently assembled in the oil pan drain opening, replacing the standard solid drain plug. This oil-pan connector also includes a flow valve. The other part connects with the drain apparatus. When the two parts are connected together, they provide a flowpath for the oil to be drained from the oil pan, when the flow valve is open. Oil-pan drain openings on different vehicles may differ in size or type, and thus, the third part of the connector device is an adapter that enables connectors of various sizes and shapes to be connected to a standard size drain connector. The adapter is screwed onto the connector part that is fitted in the drain pan opening and mates easily and conveniently with the standardized connector that connects to the drain apparatus.
The disclosed connector device has several disadvantages. The fact that no means are provided to prevent one from detaching the connector of the drain apparatus from the oil pan connects the while the flow valve is open is a serious safety risk. Another disadvantage is that the service operator must first check for the size and type of adapter needed to fit the particular oil-pan source connector, and fetch and mount the adapter on the source connector before attaching the drain apparatus. This is time-consuming and, thus, cost-inefficient. A further disadvantage of the disclosed connector device is that an addtional pressure-actuated valve is incorporated into the part of the connector that connects to the drain apparatus. The drain apparatus includes a negative pressure system that assists the evacuation of the oil from the oil pan and the valve is used to apply the negative pressure to the flowpath. Incorporating this valve into the connector device itself, however, increases greatly the manufacturing cost of the connector device and also introduces an additional source of failure at this critical point. This pressure-actuated valve can be placed at any number of other places in the drain apparatus, where it is easier and simpler to install and maintain.
Conventional source-container connectors, i.e., connectors attached to the container to be drained, typically include multiple components and are constructed to be disassemblable, either to permit adaptation of the source-container connector to a number of different connectors and/or to permit replacement of the components. The source-container connector fulfills a critical function with regard to safety and efficiency in the material transfer process and providing a connector that is disassemblable introduces a source of failure, and, thus, is undesirable. Furthermore, a disassemblable connector is generally more costly to manufacture, as the design of the device is more complex.
Most connectors for industrial applications include some provision to prevent the flow valve on the source-container from being accidentally or unintentionally opened. No provision is made, however, to prevent accidental or unintentional closure of the valve. Closing a valve during processing of flowable material, particularly when pressure forces are involved to generate or assist flow, may cause degradation or failure of the source and/or destination containers and conduit on either side of the valve.
What is needed, therefore, is a system and device for safely and reliably transferring a flowable material from one container to another. What is further needed is such a device that is simple and quick to operate and is economic in its fabrication. What is yet further needed is such a device that effectively prevents an unintentional disconnection of the device while the flow valve is open. What is still further needed is such a device that reduces the risk of unintentional opening of the flow valve when the system is not connected, and unintentional closing of the valve during material transfer.